One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,3)(4,7,8,6)(9,10,14,18)(11,16,19,15)(12,13,17,23)(20,22,24,21)(25,26)(27,35)(28,34)(29,31)(30,33)(32,36)(37,39)(38,40)(2,3)(6,7)(11,19)(15,16)(20,24)(21,22)(25,27,32,30)(26,33,36,35)(28,37,29,38)(31,39,34,40)(1,3,5,2)(4,7,8,6)(9,11)(10,15)(12,20)(13,21)(14,19)(16,18)(17,24)(22,23)(25,28,32,29)(26,34,36,31)(27,37,30,38)(33,40,35,39)(1,4,5,8)(2,6,3,7)(9,11)(10,16)(12,20)(13,22)(14,19)(15,18)(17,24)(21,23)(25,29,32,28)(26,34,36,31)(27,38,30,37)(33,40,35,39)(9,12,14,17)(10,13,18,23)(11,20,19,24)(15,21,16,22)(25,30,32,27)(26,35,36,33)(28,38,29,37)(31,40,34,39)(9,13)(10,17)(11,21)(12,18)(14,23)(15,24)(16,20)(19,22)(25,31,32,34)(26,29,36,28)(27,39,30,40)(33,38,35,37)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.